An automotive electrical system is a formidable combination of high-current and low-current circuitry. In many cases, relays are required for control purposes. In addition, all circuits must typically be adequately fused (e.g., to protect expensive components and to guard against the danger of fire). In order to facilitate the replacement of fuses and relays, and to simplify interconnection of electrical hardware, many different electric power distribution systems have been tried.
One approach that has been tried is to centralize the mounting of fuses and relays and then route input and output connections from this central location. The first systems built using this approach typically included a great deal of point-to-point wiring. Hand wiring is very costly, and manual wiring operations are typically a source of wiring errors that negatively impact product quality.
Another approach that has been tried has been the construction of customized distribution networks stamped from thin metal sheets. These stampings are shaped so that contact tabs protrude through openings in custom designed plastic shells. Although this approach typically yields a higher quality product, tooling costs can be high for both the plastic shells and the stampings since virtually every automobile model typically requires a unique distribution system. At least some of this uniqueness aspect is driven by the proliferation of fuse and relay packages. A distribution product must typically be able to accommodate the fuse and relay components selected by the automobile manufacturer.
Another approach centered around the use of flexible circuit board technology, or “flex circuits.” Flex circuits are constructed by depositing conductive material between two flexible insulating layers. Although the unique distribution requirements of each vehicle model would typically require unique flex circuits for each application, tooling costs are typically much lower than the metal stamping/custom plastic housing approach described previously. One disadvantage of the flex circuit approach is that the conductive layers are typically very thin, and the high current densities often required in vehicle power distribution can lead to overheating and possible eventual failure.
In addition, it is noted that within a vehicle electrical system there is typically a need to pass electrical current between a passenger compartment and an engine compartment. This typically requires circuit(s) to pass through a dash panel (or bulkhead) in some manner, which in turn typically creates a need to seal the junction point(s) to prevent water intrusion into the passenger compartment.
In this regard, one conventional method for accomplishing such passing through the bulkhead utilizes an applied or molded on grommet to pass a wire harness directly through the bulkhead. Another conventional method for accomplishing such passing through the bulkhead utilizes a bulkhead connector, which is a connector that is attached directly to and seals against the bulkhead—in this example half of the connector is in the passenger compartment and the other half is in the engine compartment. It is believed that both of these conventional methods require any circuit protection devices to be located elsewhere in the vehicle. Further, it is believed that neither of these conventional methods provides multiple harness junction capability.
Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. The figures constitute a part of this specification and include illustrative embodiments of the present invention and illustrate various objects and features thereof.